package day02;

import java.io.*;

public class Test03 {
    public static void main(String[] args) throws IOException {
        File dir = new File(".");
        File[] subs = dir.listFiles(f->f.getName().endsWith(".txt"));
        for(File sub : subs){
            String filename = sub.getName();
            String name = filename.substring(0,filename.lastIndexOf("."));
            name = name +"_cp";
            name = name + filename.substring(filename.lastIndexOf("."));

            FileInputStream fis = new FileInputStream(sub);
            FileOutputStream fos = new FileOutputStream(name);
            int len;
            byte[] data = new byte[1024*10];
            while((len = fis.read(data))!=-1){
                fos.write(data,0,len);
            }
            fis.close();
            fos.close();
        }
    }
}
